JP6042700B2 - Filtration device - Google Patents

Description

  The present invention relates to a backwashable filtration device that peels off trapped substances adhering to the inner peripheral surface of a cylindrical filter element provided inside a filtration chamber, and more particularly, to an inner peripheral surface of the filter element by filtration. The present invention relates to a filtration device that can simplify the structure for backwashing to remove the trapped material and improve the backwashing efficiency of the filter element.

  Conventionally, in filtration of liquids commonly used in industries such as cooling water or process liquids of various devices, filtration of oils such as lubricating oils or diesel fuel oils, filtration of various raw material gases used in chemical factories, etc. Various filtering devices are used for the purpose of capturing and removing contained fine particles and dust.

  If filtration by the filtration device is continued for a long period of time, solid content or gel-like dust trapped in the filter element accumulates in the filter element, and resistance to a fluid flowing from the inside to the outside increases. In particular, it becomes difficult to filter the target fluid. In order to cope with this, for example, periodically, an operation called “back washing” is performed to peel off the trapped material attached to the filter element through the fluid in the direction opposite to that during filtration, thereby improving the filtration performance of the filter element. Recover.

  The backwashing operation is effective, but the trapped material adhering to the filter element may remain without being completely removed. In that case, even if the backwashing operation is repeated, the resistance to the fluid flowing from the inside to the outside of the filter element increases, and it may be difficult to filter the target fluid. In particular, when the liquid is filtered, gel-like dust or dust covered with a sticky substance is firmly attached to the surface of the filter element. It is difficult to restore the filtration performance of the filter element only by backwashing with fluid. In particular, the tendency is strong in a filtration device using a filter element whose eye size is smaller than 100 μm.

  In response to this, a filtering device for recovering the filtering performance of the filter element has been proposed. This type of filtration device includes a housing that surrounds and seals a cylindrical filter, raw water pressure supply means for supplying raw water under pressure to the raw water chamber inside the filter, and filtration from a filtrate chamber outside the filter. Discharging means for discharging the liquid, a suction nozzle provided in the raw water chamber and opening at a position facing the inner surface of the filter, and cleaning water connected to the suction nozzle and discharging the sucked waste water to the outside from the raw water chamber Discharge means, suction control means for controlling the suction of the cleaning waste water from the suction nozzle by controlling the cleaning water discharge means, nozzle moving means for moving the suction nozzle along the inner surface of the filter, and the filtrate chamber A backwashing nozzle disposed at a position facing the suction nozzle and discharging backwashing water; backwashing water supply means for supplying backwashing water under pressure to the backwashing nozzle; Having a backwashing nozzle moving means for moving the nozzle in synchronization with the suction nozzle, it has been proposed (e.g., see Patent Document 1).

JP 2004-141785 A

  However, in the conventional filtration device, in order to perform backwashing to peel off the trapped substance attached to the inner surface of the filter, the cleaning nozzle is opposed to the suction nozzle in accordance with the suction of the cleaning wastewater by the suction nozzle facing the inner surface of the filter. In order to discharge the backwash water from the backwash nozzle, it is necessary to have a suction control means for washing drainage from the suction nozzle and a backwash water supply means for supplying backwash water under pressure to the backwash nozzle. In order to reciprocate the nozzle and backwash nozzle synchronously, a mechanical mechanism that combines a suction nozzle moving means, a backwash nozzle moving means, an electric gear motor, a ball screw, and the like is required. Therefore, the structure for backwashing the filter becomes complicated, and the entire apparatus becomes large. Therefore, in practice, such a filtration device has not been used so much.

  Accordingly, the problem to be solved by the present invention that addresses such problems is to simplify the structure for backwashing to remove the trapped material adhering to the inner peripheral surface of the filter element by filtration. It is in providing the filtration apparatus which can improve the efficiency of backwashing.

In order to solve the above problems, a filtration device according to a first aspect of the present invention includes a fluid inflow chamber into which a target fluid flows from the outside, a filtration chamber that filters the target fluid that has flowed in from the fluid inflow chamber and flows out to the outside, and A casing having a drain chamber for discharging the trapped substance from the filtration chamber to the outside, a sealed space, and a filter chamber provided inside the filtration chamber, closed at one end and on the fluid inflow chamber side. is the other end opening positioned a cylindrical filter element for filtering through the fluid outward from the inside, consists of a disc-shaped member, the disc into the inner peripheral surface at the inside of the filter element the outer peripheral portion of the Jo member reciprocally movably provided in the axial direction together with the sliding contact, a gap toward the center from the outer peripheral portion in the thickness of the disc-shaped member, the filter error during backwashing The inward flow from the pressure difference between the pressure outside the instrument and the pressure of the gap occurs from the outside to the inside of the filter element in the gap, to release the captured substance attached to the inner peripheral surface of the filter element A base end is connected to one side surface of the backwashing sliding member and the disk-shaped member of the backwashing sliding member, and a piston member is provided at the other end to communicate with the gap. A fluid circulation hole is formed in the axial direction, an orifice is provided at any one of the longitudinal directions of the fluid circulation hole , and the inward flow generated in the backwashing sliding member is passed through the orifice. a backwash pipe to allow flow out toward the drain chamber, is provided along an outer periphery of said one side surface, in sliding contact with brushes some are in the inner peripheral surface of the filter element over its entire circumference And the scraper formed in the blade shape or paddle, the fitted piston member provided in the backwash pipe for reciprocal movement from one end, a reciprocating sliding member for the backwash inside of the filter element causes moved, fluid and actuating cylinder to flow toward the drain chamber, a piston member mated backwash pipe into the actuating cylinder from the backwash pipe extending other end to the drain chamber Fluid flow means for freely circulating fluid in the working cylinder, so that the pressure of the fluid outlet from the filtration chamber is higher than normal pressure and the fluid flows in. The pressure at the fluid inlet to the chamber is made higher than the pressure at the fluid outlet, and back draining is performed by opening and closing the drain port of the drain chamber to a pressure side lower than the pressure at the fluid outlet. is there.

  Furthermore, the fluid circulation means allows fluid to freely circulate in a space between a closing member provided at one end of the working cylinder and a piston member of a backwash pipe fitted in the working cylinder. Also good.

  The backwashing sliding member may be formed with one or a plurality of fluid passage holes penetrating from one side surface to the other side surface within the disk surface of the disk-shaped member.

  In addition, one backwashing sliding member is provided at one end of the backwashing pipe, and a fluid flow hole is generated due to a pressure difference between the inside and outside of the filter element at an intermediate portion in the axial direction of the backwashing pipe. It is good also as what provided one or more other backwashing sliding members comprised so that introduction of an inward flow was possible.

  The filtration device according to the second invention is a fluid inflow chamber into which the target fluid flows from the outside, a filtration chamber for filtering the target fluid flowing in from the fluid inflow chamber and outflowing to the outside, and an object captured by the filtration of the filtration chamber In the casing having a drain chamber for discharging the outside to the outside in the sealed space, the filter element of each means in the first invention, the backwashing sliding member, the backwashing pipe, and the operation A plurality of unit filtration units in which a cylinder and a fluid circulation means are combined together are arranged in parallel.

  Further, the unit filtration unit may be divided into a plurality of groups including one or a plurality of unit filtration units, and the drain chamber in which the other end portion of the working cylinder of the unit filtration unit in each group is positioned may be partitioned for each group. .

According to the first invention, in the filter element provided in the inside of the filtration chamber, the fluid passes through and filters from the inside to the outside, and the outer peripheral portion slides on the inner peripheral surface of the filter element. A backwashing sliding member that is in contact with and reciprocally movable in the axial direction captures adhering to the inner peripheral surface of the filter element due to an inward flow caused by a pressure difference between the inside and outside of the filter element during backwashing. The base end is connected to one side surface of the backwashing sliding member and the other end is provided with a piston member and any one of the longitudinal directions of the fluid circulation holes formed in the axial direction. A piston member provided in the backwashing pipe that allows an inward flow generated during backwashing by the backwashing sliding member to flow out toward the drain chamber by a backwashing pipe provided with an orifice in the backwashing pipe The The backwashing sliding member is reciprocally moved inside the filter element so as to be reciprocally movable from the end portion, and the fluid is circulated by the fluid circulation means in the working cylinder whose other end portion extends into the drain chamber. The piston member of the backwash pipe fitted in the working cylinder can be reciprocally moved freely, the pressure of the fluid outlet from the filtration chamber is made higher than the normal pressure, and the fluid inlet of the fluid inlet chamber The fluid from the backwash pipe is directed to the drain chamber by making the pressure higher than the pressure at the fluid outlet and opening and closing the drain port of the drain chamber to the pressure side lower than the pressure at the fluid outlet. The trapped material obtained by filtration in the filtration chamber can be discharged to the outside from the drain chamber.
In this case, the movement of the backwashing sliding member that peels off the trapped substance adhering to the inner peripheral surface of the filter element allows the fluid to freely flow in the working cylinder by the fluid circulation means, and puts the drain chamber into a discharged state. Therefore, a complicated mechanical mechanism is not necessary. Therefore, it is possible to simplify the structure for backwashing to remove the trapped substances attached to the inner peripheral surface of the filter element by filtration, and to improve the backwashing efficiency of the filter element. In addition, the working cylinder serves as a cylinder for reciprocating the piston member of the backwash pipe, and also serves as a drain pipe for flowing the fluid from the backwash pipe toward the drain chamber. It is possible to reduce the space and save space. Thereby, the whole apparatus can be reduced in size.

  According to the second invention, the filter element according to the first invention, the backwashing sliding member, the backwashing pipe, the working cylinder, and the fluid circulation means are integrally combined in the casing. By arranging a plurality of unit filtration units in parallel, the throughput of filtration can be increased. Moreover, drain amount and backwashing efficiency can be improved by controlling each unit filtration unit arrange | positioned in parallel separately. Furthermore, a larger filtration area can be obtained even with the same volume.

It is a center longitudinal cross-sectional view which shows the embodiment of the filtration apparatus by 1st invention, and the state of each component at the time of filtration. It is an expanded sectional view which shows the sliding member for backwashing of the said filtration apparatus, and the pipe for backwashing partially partially. It is a side view which shows the two disk-shaped members which comprise the said sliding member for backwashing, (a) is a left view of FIG. 2 which shows a 1st disk-shaped member, (b) is a 2nd disk shape. It is a right view of FIG. 2 which shows a member. It is an expanded sectional view which shows the structure of the pipe for backwashing of the said filtration apparatus, an action | operation cylinder, and a closure member. It is explanatory drawing which shows the state of the filter element at the time of backwashing, the sliding member for backwashing, the pipe for backwashing, and an action | operation cylinder. It is explanatory drawing which shows a state when returning the sliding member for backwashing to an initial state. It is a principal part expanded sectional view which shows 2nd Embodiment of the sliding member for backwashing. It is principal part expansion explanatory drawing which shows 3rd Embodiment of the sliding member for backwashing. It is explanatory drawing which shows the shape of the 1st and 2nd disk shaped member in the sliding member for backwashing of 3rd Embodiment, and a structure, (a) is a left view of a 1st disk shaped member, (b ) Is a cross-sectional view taken along line XX of (a), (c) is a right side view of the second disk-shaped member, and (d) is a cross-sectional view taken along line YY of (c). It is a center longitudinal cross-sectional view which shows other embodiment of the filtration apparatus by 1st invention. It is a principal part expanded sectional view which shows 2nd Embodiment of the pipe for backwashing in the said filtration apparatus. It is a principal part expanded sectional view which shows 3rd Embodiment of the pipe for backwashing in the said filtration apparatus. It is a center longitudinal cross-sectional view which shows embodiment of the filtration apparatus by 2nd invention. It is the ZZ sectional view taken on the line of FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a diagram showing an embodiment of a filtration device according to the first invention. This filtration device is a filtration of liquids commonly used in the industry such as cooling water or process liquid of various devices, filtration of oils such as lubricating oil or diesel fuel oil, filtration of gases etc. of various raw materials used in chemical factories, Alternatively, it can be applied to the filtering of ship ballast water, and it can be backwashed to remove trapped substances adhering to the inner peripheral surface of the filter element while capturing and removing fine particles and dust contained in them. As shown in FIG. 3, the casing 1, the filter element 2, the backwashing sliding member 3, the backwashing pipe 4, the working cylinder 5, and the fluid circulation means 6 are provided.

  The casing 1 forms an outer shell of the filtration device, and is formed in a cylindrical shape (for example, a cylindrical shape) in which one end portion and the other end portion are closed, a rectangular parallelepiped shape, and the like, and has a sealed space inside. Yes. The inside of the casing 1 is partitioned into three chambers by a first partition plate 7a and a second partition plate 7b arranged at two intermediate positions in the longitudinal direction. Between the first partition plate 7a and the second partition plate 7b, there is a fluid inflow chamber 8 into which the target fluid flows from the outside, and between the second partition plate 7b and the end plate 9 at one end, It has a filtration chamber 10 for filtering the target fluid flowing in from the fluid inflow chamber 8 to flow out to the outside, and trapped by filtration of the filtration chamber 10 between the first partition plate 7a and the end plate 11 at the other end. It has a drain chamber 12 for discharging things to the outside. The material of the casing 1 is metal, synthetic resin, or the like, and the shape and size of the casing 1 may be appropriately determined according to the purpose of use of the filtration device, the type and amount of liquid and gas to be passed, the installation location, and the like.

  A fluid inlet 13 is provided in a part of the fluid inflow chamber 8. The fluid inlet 13 is formed in a pipe shape protruding outward, and its tip is formed in a flange shape, to which a fluid supply pipe (not shown) is connected. A fluid outlet 14 is provided in a part of the filtration chamber 10. The fluid outlet 14 is shaped like a pipe projecting outward, and its tip is shaped like a flange, to which a filtered fluid discharge pipe (not shown) is connected. Further, a drain port 15 is provided in a part of the drain chamber 12. The drain port 15 is formed in a pipe shape protruding outward, and the tip thereof is formed in a flange shape, to which a captured matter discharge pipe (not shown) is connected. For example, a circular through hole 16 is formed at the center of the second partition plate 7b.

  A filter element 2 is provided inside the filtration chamber 10. This filter element 2 is used to pass a target fluid and capture and filter solids contained in the fluid, gel-like dust, etc., and is formed into a cylindrical shape as a whole, and one end thereof is blocked. In addition, the other end located on the fluid inflow chamber 8 side is opened so that the fluid passes from the inside toward the outside and is filtered. That is, in the filter element 2, one end portion located on the left side in FIG. 1 is held and closed by the sealing member 17, and the other end portion opened on the right side is the through hole 16 of the second partition plate 7b. Is bound to.

  The sealing member 17 of the filter element 2 closes one end of the filter element 2 and also functions to maintain the shape of the filter element 2. A support shaft 18 that protrudes to the left at the center of the sealing member 17 is supported by a steady plate 19 provided near the end plate 9 at one end of the casing 1. Thus, one end of the filter element 2 is supported inside the filtration chamber 10 using the buffering action of the steady plate 19. In FIG. 1, reference numeral 38 indicates a ring-shaped flange provided on the outer periphery of one end of the casing 1, and reference numeral 39 indicates a ring-shaped packing interposed between the end plate 9 and the flange 38. Yes. The method of sealing the filter element 2 is an example, and the other end side of the filter element 2 coupled to the through hole 16 of the second partition plate 7b may be removed. The filter element 2 only needs to be able to be filtered and a backwashing sliding member 3 to be described later can be operated therein.

  The filter element 2 is composed of a plurality of metal meshes sintered to improve shape retention and formed into a cylindrical shape, or a metal fiber or resin nonwoven fabric and / or a metal mesh or resin mesh. Furthermore, there are a cylindrical notch wire filter element, a wedge wire filter element, a plate member having pores, and the like. The metal fiber non-woven fabric is prepared by laminating and sintering metal fibers, and fulfills the function of adhering dust or the like contained in the fluid to be filtered to form a clean fluid. In addition, the metal mesh may perform a filtering function, or may function as a shape-retaining support material or a surface protection material for the metal fiber nonwoven fabric. The shape, size, number, and the like of the filter element 2 may be appropriately determined according to the purpose of use of the filtration device, the filtration performance, the size of the casing 1, the type of the target fluid, and the like.

  Inside the filter element 2, a backwashing sliding member 3 is provided so as to reciprocate in the axial direction of the filter element 2. The sliding member 3 for backwashing has an outer peripheral portion that is in sliding contact with the inner circumferential surface of the filter element 2 and is in contact with the filter element 2 due to an inward flow caused by a pressure difference between inside and outside at the time of backwashing. The trapped material adhering to the inner peripheral surface is peeled off. The backwashing sliding member 3 is formed of a metal or the like into a disk-shaped member, and a gap through which fluid flows inward due to a pressure difference between the inside and outside of the filter element 2 from the outer peripheral portion toward the central portion within the thickness. This gap communicates with a fluid circulation hole of the backwash pipe 4 described later. The outer diameter of the disk-shaped member is set to a size that fits into the inner periphery of the cylindrical filter element 2 and can be in sliding contact with the inner peripheral surface.

  A backwash pipe 4 is connected to one side of the backwash sliding member 3. The pipe 4 for backwashing allows the inward flow generated by the sliding member 3 for backwashing to flow out toward the drain chamber 12, and is formed in a straight line as a whole, and its base end is used for backwashing. The piston member 20 is connected to one side of the sliding member 3, and the other end is provided with a piston member 20, and the orifice 28 is provided at any one position in the longitudinal direction of the fluid flow hole 21 formed in the axial direction, for example, on the outlet side. Is provided. The orifice 28 limits the backwash flow rate that flows in the fluid circulation hole 21 toward the drain chamber 12, and thereby limits the pressure loss due to the piping after the drain chamber 12.

  Specific shapes and structures of the backwashing sliding member 3 and the backwashing pipe 4 are configured as shown in FIGS. FIG. 2 is an enlarged cross-sectional view showing the backwashing sliding member 3 and the backwashing pipe 4 partially in cross section. FIG. 3 is a side view showing two disk-shaped members constituting the backwashing sliding member 3.

  In FIG. 2, the backwashing sliding member 3 is configured by combining a first disk-shaped member 3a having a predetermined thickness and a second disk-shaped member 3b having a predetermined thickness. As shown in FIG. 3A, the first disk-shaped member 3a has a bolt hole 22 through which a bolt is passed at a position close to the outer peripheral portion, for example, at a position corresponding to 2 to 4 equal parts in the circumferential direction. ing. As shown in FIG. 3 (b), the second disk-shaped member 3b has a bolt hole 23 through which a bolt is similarly passed at a position corresponding to the bolt hole 22 of the first disk-shaped member 3a. A coupling hole 24 having an inner diameter capable of fitting the backwash pipe 4 is formed.

  As shown in FIG. 2, the two disk-shaped members 3 a and 3 b are arranged such that a bolt 25 is inserted into the bolt holes 22 and 23 with a spacer 25 interposed therebetween, and a nut 27 is connected to the other end of the bolt 26. Are screwed together. Therefore, the backwashing sliding member 3 is assembled in parallel between the two disk-shaped members 3a and 3b with a distance corresponding to the length of the spacer 25, and this distance is a disk-shaped member (3a and 3b). The gap 25g that produces an inward flow from the outer peripheral portion toward the central portion within the thickness of the inner portion is formed.

  In FIG. 2, the backwash pipe 4 is connected at its base end to a coupling hole 24 formed in the second disk-like member 3b of the backwash sliding member 3 by welding or the like, and its axial direction. A fluid circulation hole 21 is formed in the upper part. Moreover, the piston member 20 is attached to the other end by welding or the like. The piston member 20 is fitted in an operating cylinder 5 described later to reciprocate the backwashing sliding member 3 inside the filter element 2, and has an outer diameter on the inner periphery of the operating cylinder 5. The size is such that it can be fitted and slidably contacted with the inner peripheral surface. An orifice 28 on the same axis as the fluid circulation hole 21 is bored at the center of the piston member 20. Accordingly, the backwashing pipe 4 causes the piston member 20 to reciprocate the backwashing sliding member 3 inside the filter element 2 and allows the backwashing sliding member 3 to flow inwardly through the gap 25g of the backwashing sliding member 3. The generated fluid can be allowed to flow out toward the drain chamber 12.

  In FIG. 1, the piston member 20 of the backwash pipe 4 is fitted in the working cylinder 5 so as to be reciprocally movable. The working cylinder 5 reciprocates the backwashing sliding member 3 inside the filter element 2 and causes the fluid from the backwashing pipe 4 to flow toward the drain chamber 12, and has one end portion of the fluid. Located in the inflow chamber 8, the piston member 20 provided in the backwash pipe 4 is fitted so as to be able to reciprocate from the one end portion, and the other end portion extends linearly into the drain chamber 12. ing.

  The specific shape and structure of the working cylinder 5 is configured as shown in FIG. FIG. 4 is an enlarged cross-sectional view showing the backwash pipe 4 and the working cylinder 5. The actuating cylinder 5 is provided with a closing member 29 at one end on the left side shown in FIG. 4 to prevent fluid leakage at the one end. A hole for fitting the backwash pipe 4 is formed in the central portion of the closing member 29, and the backwash pipe 4 is fitted so as to be reciprocally movable. A sealing material is interposed on the inner periphery of the hole into which the backwash pipe 4 is fitted. A piston member 20 attached to the backwash pipe 4 is fitted to the other end portion side of the working cylinder 5. Therefore, a space 30 is formed between the closing member 29 and the piston member 20 in the working cylinder 5. Note that the other end portion on the right side of the working cylinder 5 shown in FIG. 4 extends into the drain chamber 12 and is opened as shown in FIG. As a result, the fluid that has generated an inward flow in the gap 25g of the backwashing sliding member 3 shown in FIG. 1 passes through the fluid flow hole 21 of the backwashing pipe 4, the orifice 28 of the piston member 20, and the working cylinder 5. It will flow toward the drain chamber 12 through.

  As shown in FIG. 1, a fluid circulation means 6 is connected to the closing member 29 of the working cylinder 5. The fluid circulation means 6 allows the piston member 20 of the backwash pipe 4 fitted in the working cylinder 5 to reciprocate within the working cylinder 5, and allows the fluid to freely flow through the working cylinder 5. It consists of a pipe, a tube, etc., and the base 31 at the tip is connected to one place of the closing member 29. The fluid circulation means 6 is a base released to normal pressure (for example, atmospheric pressure). The fluid circulation means 6 is not limited to atmospheric release, and may be connected to a pipe through which a liquid such as normal pressure water or oil flows.

  The structure of the closing member 29 to which the base 31 of the fluid circulation means 6 is connected will be described with reference to FIG. In FIG. 4, the hole formed in the central portion of the closing member 29 has an inner diameter larger than the outer diameter of the backwash pipe 4 at the right half facing the space 30 in the working cylinder 5. A gap 32 is formed between the outer peripheral surface of the pipe 4. The gap 32 communicates with the space 30 in the working cylinder 5. A flow hole 33 is formed within the thickness of the blocking member 29 at one location, and a female screw is cut on the inner peripheral surface of the flow hole 33. In this state, as shown in FIG. 1, the male screw of the base 31 of the fluid circulation means 6 is screwed into the circulation hole 33, and the fluid circulation means 6 is connected to one place of the closing member 29. Therefore, the fluid circulation means 6 allows fluid to enter the space 30 between the closing member 29 provided at one end of the working cylinder 5 and the piston member 20 of the backwash pipe 4 fitted in the working cylinder 5. Can be freely distributed. That is, the fluid in the space 30 can be freely taken in and out.

  In the configuration of the filtration device as described above, the pressure of the fluid outlet 14 from the filtration chamber 10 (that is, the outlet side pressure of the filter element 2) is made higher than normal pressure (for example, atmospheric pressure), and the fluid inflow chamber The pressure of the fluid inlet 13 to 8 (that is, the pressure on the inlet side of the filter element 2) is made higher than the pressure of the fluid outlet 14. In order to make the pressure of the fluid outlet 14 higher than the normal pressure, the piping resistance on the downstream side of the fluid outlet 14 may be increased. For example, the outlet valve is throttled, a back pressure valve is provided, the pipe is raised and the head (water head) is enlarged. Further, in order to make the pressure at the fluid inlet 13 higher than the pressure at the fluid outlet 14, a pressure difference (differential pressure) generated when the fluid passes from the inside to the outside of the filter element 2 is added to the outlet pressure. That's fine. That is, the target fluid may be supplied so that the inlet pressure = the outlet pressure + the filter differential pressure. In this state, filtration is performed by opening and closing the drain port 15 of the drain chamber 12 to a pressure side lower than the pressure of the fluid outlet 14, and the filter element 2 is backwashed.

  Next, the operation of the thus configured filtering device will be described with reference to FIGS. 1, 5, and 6. FIG. FIG. 1 is an explanatory view showing the state of the filter element 2, the backwashing sliding member 3, the backwashing pipe 4 and the working cylinder 5 in the casing 1 during filtration. In this state, the backwashing sliding member 3 is positioned at the one end portion that is closest to the left side in the filter element 2, and the piston member 20 of the backwashing pipe 4 is closest to the left side in the working cylinder 5. It is located at one end, and the drain port 15 is closed by a valve (not shown) or the like. This is the initial state.

  At the time of filtration, in FIG. 1, an external target fluid is caused to flow from the fluid inlet 13 of the casing 1 as indicated by an arrow A and from the fluid outlet 14 to the outside as indicated by an arrow B. At this time, the target fluid flows into the fluid inflow chamber 8 from the fluid inlet 13, flows in the fluid inflow chamber 8 to the left side in FIG. 1, and passes through the through hole 16 formed in the second partition plate 7b. It flows into the filter element 2 and is filtered while the fluid passes from the inside toward the outside. The filtered fluid flows out to the filtration chamber 10 outside the filter element 2 and flows out from the filtration chamber 10 through the fluid outlet 14 to the outside as a filtered fluid.

  If filtration is continued in this manner, solid content or gel-like dust contained in the target fluid may be trapped by the filter element 2 and accumulated in the filter element 2 to cause clogging. If clogging has occurred, in order to restore the filtration performance of the filter element 2, backwashing is performed to peel off the trapped material adhering to the filter element 2.

  FIG. 5 is an explanatory view showing the state of the filter element 2, the backwashing sliding member 3, the backwashing pipe 4, the working cylinder 5 and the fluid circulation means 6 in the casing 1 during backwashing. At the time of backwashing, the fluid in the drain chamber 12 is opened by opening the drain port 15 opened to normal pressure (for example, atmospheric pressure) while allowing the fluid to flow in from the fluid inlet 13 and outflowing the fluid from the fluid outlet 14. To the outside. At this time, when the fluid in the drain chamber 12 flows out to the outside, the gap between the inside of the working cylinder 5, the orifice 28 of the piston member 20, the fluid flow hole 21 of the backwash pipe 4, and the backwash slide member 3. Due to the communication of 25 g, the pressure in the gap 25 g of the backwashing sliding member 3 becomes lower than the pressure outside the filter element 2. Due to the pressure difference between the inside and outside, an inward flow is generated as indicated by an arrow D from the outside to the inside of the filter element 2 through the gap 25g, and the trapping material adhering to the inner peripheral surface of the filter element 2 is peeled off. Washing is started, and backwash fluid is ejected from the orifice 28.

  The separated captured matter is ejected from the gap 25g of the backwashing sliding member 3 through the fluid flow hole 21 of the backwashing pipe 4 and the orifice 28 of the piston member 20 as shown by the arrow E, and the working cylinder 5 is ejected. Through the drain chamber 12 and discharged from the drain chamber 12 to the outside as indicated by an arrow C. The pressure difference between the fluid inlet 13 and the fluid outlet 14 when the backwashing is started is, for example, about 10 to 100 kPa. However, it is not limited to this range, and it is designed with appropriate changes according to the target fluid to be filtered.

  In the backwashing shown in FIG. 5, the backwashing sliding member 3 is moved to the right in the filter element 2 because the sealing member 17 of the first disk-like member 3 a in the backwashing sliding member 3 is used. This is the difference between the pressure on the side and the pressure in the drain chamber 12. The pressure difference should be as large as possible. Therefore, what is necessary is just to make the pressure of the fluid outlet 14 higher than a normal pressure. For example, the outlet valve is throttled, a back pressure valve is provided, the pipe is raised and the head (water head) is enlarged. Here, the fluid circulation means 6 allows the fluid to freely flow through the working cylinder 5 as indicated by arrows F and G. Therefore, as shown in FIG. 4, backwashing fitted into the working cylinder 5 is performed. The piston member 20 of the working pipe 4 can freely reciprocate within the working cylinder 5. Thereby, the whole backwashing sliding member 3 moves to the right in the filter element 2 due to the pressure difference.

  At this time, the outer peripheral portion of the backwashing sliding member 3 is in sliding contact with the inner peripheral surface of the filter element 2 and an inward flow is generated from the outer side to the inner side of the filter element 2. Backwash while removing the trapped material adhering to the peripheral surface. In this way, the backwashing sliding member 3 is backwashed until it reaches the other end on the right side of the filter element 2. Even during the backwashing, the filter element 2 is not efficiently filtered on the left side of the backwashing sliding member 3, but when the structure shown in FIG. Similarly, it can be continuously executed.

  FIG. 6 is an explanatory view showing a state when the backwashing sliding member 3 is returned to the initial state. In this state, the backwashing sliding member 3 is positioned at the other end portion that is closest to the right side in the filter element 2, and the piston member 20 of the backwashing pipe 4 is closest to the right side in the working cylinder 5. Located at the other end. In such a state, the backwashing sliding member 3 is in a state of closing the through hole 16 of the second partition plate 7b, and the target fluid passes through the through hole 16 as shown in FIGS. It becomes difficult to flow into the filter element 2 and filtration by the filter element 2 becomes impossible. Therefore, it is necessary to return the backwashing sliding member 3 to the initial state shown in FIG.

  In this case, the drain port 15 is closed with the fluid flowing in from the fluid inlet 13 and the fluid flowing out from the fluid outlet 14. Therefore, the discharge of the fluid from the drain chamber 12 is stopped. That is, by stopping the valve connected to the drain port 15, the pressures in the filtration chamber 10 and the drain chamber 12 that are in communication with each other become the same, and the flow through the orifice 28 of the piston member 20 is stopped. Then, the piston member 20 receives the pressure of the drain chamber 12. Here, since the fluid circulation means 6 is opened to the atmosphere, for example, the fluid in the space 30 in the working cylinder 5 is discharged to the outside as indicated by the arrow G by the pressure of the drain chamber 12. Further, when the fluid flows in from the fluid inlet 13, a pressure difference of the fluid that tries to flow into the filter element 2 from the through hole 16 formed in the second partition plate 7 b is also applied. As a result, the entire backwashing sliding member 3 moves to the left as indicated by the arrow H in the filter element 2. In this way, the backwashing sliding member 3 moves to the left end of the filter element 2. Thereby, the sliding member 3 for backwashing returns to the initial state shown in FIG. Thereafter, the target fluid is filtered as shown in FIG. 1, and the filter element 2 is back-washed as shown in FIG.

  In the case of FIG. 6, the drain opening 15 may be slightly opened, and the backwashing sliding member 3 may be returned while the filter element 2 shown in FIG. 5 is backwashed. In this case, by controlling the pressure in the filtration chamber 10, the fluid inflow chamber 8, the pressure in the drain chamber 12, or the speed of the fluid flowing in from the fluid circulation means 6, the backwashing sliding member 3 can be moved or backwashed. Can be controlled.

  FIG. 7 is an enlarged cross-sectional view showing a main part of a second embodiment of the backwashing sliding member 3. This embodiment is provided with a brush 34 that slidably contacts the inner peripheral surface of the filter element 2 along the outer peripheral portion of one or both side surfaces of the disk-like member (3a, 3b) over the entire periphery. . The brush 34 moves together when the backwashing sliding member 3 reciprocates in the axial direction inside the filter element 2 and scrapes off the trapped material adhering to the inner peripheral surface of the filter element 2. As shown in FIG. 7, the brush ring 34b is planted around the outer periphery of the channel ring 34a, and is called a ring brush. The channel ring 34 a is formed by winding a channel material having a U-shaped cross section made of metal or the like into a ring shape having an outer diameter smaller than the inner diameter of the filter element 2. In the U-shaped concave portion on the outer periphery of the channel ring 34a, brush hairs 34b whose hair tips can come into sliding contact with the inner peripheral surface of the filter element 2 are planted in a ring shape. The length of the bristles of the bristles 34b needs to be at least enough that the tips of the bristles 34b come into contact with the inner peripheral surface of the filter element 2 with a certain amount of pressure. The material of the brush bristles 34b may be anything as long as it is generally used as brush bristles such as natural or synthetic fibers, or metal wires such as steel, copper, and brass. The brush 34 is attached by connecting the channel ring 34a to the right side surface of the second disk-shaped member 3b by welding or the like.

  In addition, instead of the brush 34, if the member on the outer peripheral portion can be in sliding contact with the inner peripheral surface of the filter element 2 to remove the captured matter, for example, a metal formed in a blade shape or a spatula shape is used. Alternatively, a resin or rubber scraper may be used.

  In this embodiment, when there is a lot of highly sticky dust or fibrous dust in the target fluid to be filtered, backwashing is carried out while scraping the trapped material adhering to the inner peripheral surface of the filter element 2 with the brush 34. It is possible to back-wash with the inward flow generated by the pressure difference between the inside and outside in the gap 25g of the sliding member 3 for use. In FIG. 7, the brush 34 is provided on the right side surface of the second disk-shaped member 3b of the backwashing sliding member 3. However, the brush 34 may be provided on the left side surface of the first disk-shaped member 3a. Alternatively, it may be provided on both side surfaces of the backwashing sliding member 3. In any case, it is desirable that the fluid flow inwardly through the gap 25g of the backwashing sliding member 3 while scraping off the captured matter of the filter element 2 with the brush 34. When the brushes 34 are provided on both side surfaces of the backwashing sliding member 3, the brushes 34 may function as a seal structure with a gap 25g.

  FIG. 8 is a main part enlarged explanatory view showing a third embodiment of the sliding member 3 for backwashing. In this embodiment, one or a plurality of fluid passage holes (35, 36) penetrating from one side surface to the other side surface are formed in the disk surface of the disk-shaped member (3a, 3b). That is, in a state where a gap 25g is formed between the first disk-shaped member 3a and the second disk-shaped member 3b, a fluid passage hole that communicates from the first disk-shaped member 3a to the second disk-shaped member 3b. 35 and 36 are formed.

  FIG. 9 is an explanatory diagram showing the shapes and structures of the first and second disk-like members 3a and 3b in the backwashing sliding member 3 of the third embodiment. FIG. 9A is a left side view of the first disc-like member 3a. As shown in FIG. 3A, the first disk-shaped member 3a has bolt holes 22 through which bolts are passed, for example, at positions of 2 to 4 equal parts in the circumferential direction near the outer periphery. Have. Inside the bolt hole 22, a plurality of fluid passage holes 35 are formed at positions of, for example, 2 to 8 equal parts in the circumferential direction. Then, as shown in FIG. 9B, the edge member 37 that borders the outer periphery of each fluid passage hole 35 protrudes on the side surface of the fluid passage hole 35 facing the second disk-shaped member 3b. . The height of the edge member 37 is the same as the length of the spacer 25 shown in FIG.

  FIG. 9C is a right side view of the second disk-like member 3b. The second disk-shaped member 3b has a bolt hole 23 through which a bolt is similarly passed at a position corresponding to the bolt hole 22 of the first disk-shaped member 3a shown in FIG. A coupling hole 24 having an inner diameter capable of fitting the washing pipe 4 is formed. A fluid passage hole 36 is also formed inside the bolt hole 23 and outside the coupling hole 24 at a position corresponding to each fluid passage hole 35 of the first disk-shaped member 3a shown in FIG. Has been.

  In this state, as shown in FIG. 8, the first disc-like member 3a and the second disc-like member 3b are combined, and the edge member 37 is positioned between them as shown in FIG. The bolt 26 is inserted into the bolt holes 22 and 23, and the nut 27 is screwed to the other end of the bolt 26 to be combined. Therefore, the backwashing sliding member 3 is assembled in parallel between the two disk-shaped members 3a, 3b with a space corresponding to the height of the edge member 37, and this space is a disk-shaped member (3a, 3b). ), A gap 25g flows inwardly due to a pressure difference between the inside and outside from the outer periphery toward the center.

  In this embodiment, at the time of backwashing shown in FIG. 5, the backwashing sliding member that moves in the direction opposite to the flow of the fluid flowing from the other end that is located on the right side of the filter element 2 and opens. Therefore, the fluid flow can be passed through the fluid passage holes 35 and 36. Thereby, filtration can be continued even at the time of backwashing. Further, the presence of the fluid passage holes 35 and 36 makes it difficult for the backwashing sliding member 3 to be subjected to a differential pressure between the fluid inlet 13 and the fluid outlet 14.

FIG. 10 is a view showing another embodiment of the filtration device according to the first invention. This embodiment uses the backwashing slide at one end of a backwashing pipe 4 in the filtration device shown in FIG. 1 using the backwashing sliding member 3 of the third embodiment shown in FIGS. 8 and 9. One member (3 ₁ ) is provided, and an inward flow generated by a pressure difference between the inside and outside of the filter element 2 can be introduced into the fluid circulation hole 21 at the axially intermediate portion of the backwash pipe 4 One or a plurality of other backwashing sliding members (3 ₂ ) are provided.

Specifically, the length of the filter element 2 is formed to be twice or three times longer than that in the case of FIG. 1, for example, and the length of the backwash pipe 4 is also increased. A first backwashing sliding member 3 _{1 having the} same structure as that of the backwashing sliding member 3 shown in FIGS. 8 and 9 is provided at one end (the left end in FIG. 10) of the backwashing pipe 4. the provided, and the second sliding member 3 ₂ backwash provided at an intermediate portion in the axial direction of the backwash pipe 4. In this case, the axial direction of the fluid flow hole 21 of the backwash pipe 4 must be continuous over the entire length, for the second sliding member 3 ₂ backwash, Fig. 9 (a), (b) A coupling hole 24 (see FIGS. 9C and 9D) having an inner diameter capable of fitting the backwash pipe 4 is also formed in the center of the first disk-shaped member 3a shown in FIG. It is connected to the pipe 4 by welding or the like. In FIG. 10, one _second backwashing sliding member 3 ₂ is provided in the middle of the backwashing pipe 4, but this corresponds to the _second backwashing sliding member 3 ₂ . 2 or 3 or more are provided at appropriate intervals, and the backwashing sliding member 3 having two or more stages as a whole including the _first backwashing sliding member 31 is provided. May be.

  According to such an embodiment, the length of the filter element 2 can be increased to 2 times, 3 times or more as compared with the case of FIG. 1 without changing the length of the working cylinder 5. This can be realized without enlarging the overall length of the apparatus when increasing the processing amount. Further, the size of the apparatus can be increased without adding other components. Furthermore, it can be applied to the unit filtration unit 40 in the filtration apparatus according to the second invention shown in FIG. 13 described later, and the amount of filtration can be further increased.

  FIG. 11 is an enlarged cross-sectional view of a main part showing a second embodiment of the backwash pipe 4 in the filtration device according to the first invention. In the second embodiment, the orifice 28 is provided in the middle of the fluid circulation hole 21 of the backwash pipe 4. In this case, a stopper member for stopping the flow of fluid is fitted in the middle portion of the fluid circulation hole 21 in the longitudinal direction, and an orifice 28 is bored in the central portion of the stopper member. The operation of the orifice 28 is the same as that shown in FIG.

  FIG. 12 is an enlarged cross-sectional view of a main part showing a third embodiment of the backwash pipe 4 in the filtration device. In the third embodiment, the orifice 28 is provided on the inlet side of the fluid circulation hole 21 of the backwash pipe 4. In this case, the second disk-like member 3b located on the inlet side of the fluid circulation hole 21 is formed like a closing lid, and an orifice 28 is drilled in the center of the closing lid. The operation of the orifice 28 is the same as that shown in FIG. The backwash pipe 4 of the embodiment shown in FIG. 11 or FIG. 12 can be applied to any of the filtration devices shown in FIG. 1 or FIG.

  Further, as an embodiment different from the orifice 28 shown in FIGS. 2, 11, and 12, instead of providing the orifice 28 at any one position in the longitudinal direction of the fluid flow hole 21 of the backwash pipe 4, The gap 25g between the first and second disk-like members 3a and 3b of the washing sliding member 3 is narrowed, and the fluid passage hole 21 of the backwash pipe 4 passes through the gap 25g to the drain chamber 12 side. The resistance of the fluid flowing through the pipe may be increased.

  FIG. 13 is a diagram showing an embodiment of a filtration device according to the second invention. The filtration device includes a fluid inflow chamber 8 into which a target fluid flows from the outside, a filtration chamber 10 that filters the target fluid that flows in from the fluid inflow chamber 8 and flows out to the outside, and a trapped object by filtration in the filtration chamber 10. In the casing 1 having a drain chamber 12 for discharging the air to the outside, in the sealed space, the filter element 2 in the first invention, the backwashing sliding member 3, the backwashing pipe 4, A plurality of unit filtration units 40 in which the working cylinder 5 and the fluid circulation means 6 are combined together are arranged in parallel.

  In FIG. 13, the casing 1 forms an outer shell of the filtration device, and is formed in a bottomed and covered cylindrical shape (for example, a cylindrical shape), a rectangular parallelepiped shape, or the like, and has a space sealed inside. FIG. 13 shows an example in which it is formed in a vertical cylindrical shape having a larger diameter than that shown in FIG. The inside of the casing 1 is partitioned into three chambers by a first partition plate 7a, a second partition plate 7b, and an end plate 9 disposed in the middle in the vertical direction. Between the first partition plate 7a and the second partition plate 7b, there is a fluid inflow chamber 8 into which the target fluid flows from the outside, and between the second partition plate 7b and the end plate 9 at one end, It has a filtration chamber 10 for filtering the target fluid flowing in from the fluid inflow chamber 8 to flow out to the outside, and trapped by filtration of the filtration chamber 10 between the first partition plate 7a and the end plate 11 at the other end. It has a drain chamber 12 for discharging things to the outside. The material of the casing 1 is metal, synthetic resin, or the like, and the shape and size of the casing 1 may be appropriately determined according to the purpose of use of the filtration device, the type and amount of liquid and gas to be passed, the installation location, and the like. In FIG. 13, reference numeral 43 indicates a mounting bracket for mounting the filter element 2 to the second partition plate 7b.

  A fluid inlet 13 is provided in a part of the fluid inflow chamber 8, and a fluid supply pipe (not shown) is connected to the fluid inlet 13. A fluid outlet 14 is provided in a part of the filtration chamber 10, and a filtration fluid discharge pipe (not shown) is connected to the fluid outlet 14. Further, a drain port 15 is provided in a part of the drain chamber 12, and a trapped material discharge pipe (not shown) is connected to the drain port 15. Reference numeral 19 denotes a steady plate provided near the end plate 9 at one end of the casing 1. In addition, although not shown in the drawings, the fluid circulation means 6 of each unit filtration unit 40 is connected to a pipe, a tube, or the like that is released to normal pressure (for example, atmospheric pressure). The fluid circulation means 6 is not limited to atmospheric release, and may be connected to a pipe through which a liquid such as normal pressure water or oil flows.

In the configuration of the filtration device according to the second invention as described above, the pressure at the fluid outlet 14 from the filtration chamber 10 is made higher than the normal pressure (for example, atmospheric pressure) as in the first invention, and the The pressure of the fluid inlet 13 to the fluid inflow chamber 8 is made higher than the pressure of the fluid outlet 14. In order to make the pressure of the fluid outlet 14 higher than the normal pressure, the piping resistance on the fluid outlet 14 side may be increased. In this state, the filter element 2 is back-washed by opening and closing the drain port 15 of the drain chamber 12 to a pressure side lower than the pressure of the fluid outlet 14.
Thus, the amount of filtration processing can be increased by arranging a plurality of unit filtration units 40 in parallel inside the large-diameter casing 1.

  Here, in the second invention, the drain chamber 12 is divided into a plurality of groups including one or a plurality of the unit filtration units 40 and the other end of the working cylinder 5 of the unit filtration unit 40 in each group is located. Is divided for each group. That is, as shown in FIG. 14, a first partition plate 41a and a second partition plate 41b are provided in the middle of the drain chamber 12, and the drain chamber 12 is made up of the first drain chamber 12a, the second drain chamber 12b, and It is divided into three third drain chambers 12c. Thereby, in the example of FIG.13 and FIG.14, ten unit filtration units 40 in total are divided into three groups. For example, a first group including three unit filtration units 40 in which the other end of the working cylinder 5 is located in the first drain chamber 12a, and the other end of the working cylinder 5 in the second drain chamber 12b. A second group that includes four unit filtration units 40 in which the other end of the working cylinder 5 is located in the third drain chamber 12c, and a third group that includes three unit filtration units 40 in which the other end of the working cylinder 5 is located. It is divided into.

  As shown in FIG. 14, a drain port 15a is provided in a part of the first drain chamber 12a, and a drain port 15b is provided in a part of the second drain chamber 12b, so that a third drain chamber is provided. A drain port 15c is provided in a part of 12c. Reference numerals 42a, 42b, and 42c denote drain valves provided in the drain ports 15a, 15b, and 15c, respectively. Thereby, the back washing operation of the unit filtration units 40 belonging to each group can be controlled separately for each group by controlling the opening and closing of the drain valves 42a, 42b, and 42c.

  In the case of the embodiment shown in FIGS. 13 and 14, by performing the backwash operation in three times for each group, it is possible to perform an operation with little fluctuation in the backwash amount and the filtration amount. This is because the backwashing fluid in the filtration device of the present invention is part of the fluid that was originally filtered, so performing backwashing discards part of the filtered fluid. Therefore, for example, if the filter elements 2 in 10 unit filtration units 40 are backwashed simultaneously, a large amount of filtered fluid is temporarily discharged to the outside as backwash fluid. Therefore, for example, if 10 unit filtration units 40 are divided into a plurality of groups and the backwash operation is performed by ordering each group, it is possible to temporarily prevent a large amount of filtered fluid from being discharged to the outside as backwash fluid. It is.

  In the above description, as shown in FIGS. 2 and 8, etc., the backwashing sliding member 3 is the same as the first disk-shaped member 3a having a predetermined thickness and the second disk-shaped having the same predetermined thickness. However, the present invention is not limited to this, and one disk-shaped member 3 having a thickness that is a combination of the first disk-shaped member 3a and the second disk-shaped member 3b. A gap (or a slit, a hole, etc.) in a radial arrangement in which an inward flow is generated by a pressure difference between the inside and outside of the filter element 2 within the width of the thickness is formed, and this gap is a fluid of the backwash pipe 4 You may comprise so that it may connect with the circulation hole 21. FIG.

1 ... casing 2 ... filter element 3 ... backwash slide member 3 ₁ ... first backwash slide member 3 ₂ ... second backwash slide member 3a ... first disk member 3b ... first 2 disk-shaped member 4 ... backwash pipe 5 ... working cylinder 6 ... fluid flow means 8 ... fluid inflow chamber 10 ... filtration chamber 12, 12a, 12b, 12c ... drain chamber 13 ... fluid inlet 14 ... fluid outlet 15, 15a , 15b, 15c ... Drain port 20 ... Piston member 21 ... Fluid flow hole 24 ... Coupling hole 25 ... Spacer 25g ... Gap 28 ... Orifice 29 ... Closure member 30 ... Space 34 ... Brush 35, 36 ... Fluid passage hole 37 ... Edge member 40 ... Unit filtration unit 41a ... First partition plate 41b ... Second partition plate

Claims (6)

A fluid inflow chamber into which the target fluid flows from the outside, a filtration chamber for filtering the target fluid that has flowed in from the fluid inflow chamber and flowing out to the outside, and a drain chamber for discharging the trapped substance by filtration of the filtration chamber to the outside, A casing having inside a sealed space;
A cylindrical filter element provided inside the filtration chamber, with one end closed and the other end located on the fluid inflow chamber side being opened, and fluid passing through and filtering from the inside toward the outside; ,
It is composed of a disk-shaped member, and the outer peripheral portion of the disk-shaped member is in sliding contact with the inner peripheral surface of the filter element and is reciprocally movable in the axial direction, and the outer periphery is within the thickness of the disk-shaped member. Inward flow generated from the outside of the filter element toward the inside in the gap due to the pressure difference between the pressure outside the filter element and the pressure in the gap during backwashing. The sliding member for backwashing that peels off the trapped material attached to the inner peripheral surface of the filter element,
A base end is connected to one side surface of the disk surface of the disk-shaped member constituting the backwash sliding member , a piston member is provided at the other end, and a fluid flow hole communicating with the gap is formed in the axial direction. An orifice is formed in any one of the longitudinal directions of the fluid circulation hole , and the inward flow generated by the backwashing sliding member can flow out toward the drain chamber through the orifice. And a pipe for backwashing,
A scraper that is provided along the outer peripheral portion of the one side surface and that is slidably in contact with the inner peripheral surface of the filter element over the entire circumference, or a scraper formed in a blade shape or a spatula shape,
Fitted for reciprocal movement of the piston member provided in the backwash pipe from one end, with reciprocating the sliding member for the backwash inside of the filter element, to said drain chamber other end an actuating cylinder for flowing the fluid from the backwash pipe toward the drain chamber extends,
Fluid circulation means for freely circulating fluid in the working cylinder in order to allow the piston member of the backwashing pipe fitted in the working cylinder to reciprocate in the working cylinder;
With
The pressure of the fluid outlet from the filtration chamber is made higher than normal pressure, the pressure of the fluid inlet to the fluid inflow chamber is made higher than the pressure of the fluid outlet, and the drain port of the drain chamber is lower than the pressure of the fluid outlet. A filtering device characterized in that backwashing is performed by opening and closing the pressure side. The fluid circulation means freely circulates fluid in a space between a closing member provided at one end of the working cylinder and a piston member of a backwash pipe fitted in the working cylinder. The filtration device according to claim 1. 2. The backwashing sliding member is formed with one or a plurality of fluid passage holes penetrating from the one side surface to the other side surface on the opposite side in the disk surface of the disk-shaped member. 2. The filtration device according to 2. One backwashing sliding member is provided at one end of the backwashing pipe, and the fluid flow hole is inwardly generated by a pressure difference between the inside and outside of the filter element at an axially intermediate portion of the backwashing pipe. 4. The filtering device according to claim 3, wherein one or a plurality of other backwashing sliding members configured to be able to introduce the flow of the above are provided . A fluid inflow chamber into which the target fluid flows from the outside, a filtration chamber for filtering the target fluid that has flowed in from the fluid inflow chamber and flowing out to the outside, and a drain chamber for discharging the trapped substance by filtration of the filtration chamber to the outside, A filter element according to any one of claims 1 to 4, a backwashing sliding member, a backwashing pipe, a working cylinder, a fluid, A filtration apparatus comprising a plurality of unit filtration units that are combined with a distribution means in parallel . The unit filtration unit is divided into a plurality of groups including one or a plurality of unit filtration units, and a drain chamber in which the other end of the working cylinder of the unit filtration unit in each group is located is partitioned for each group. Item 6. The filtration device according to Item 5.